Just got a new frame built with DA 9 sp triple. Running the DA 7700 long cage RD on 12-25, with an FSA triple, 52/39/30, and a SRAM PC-99. This is my first triple and first STI bike as well.
Shifting the cogs is very quick with just a tap,whether up or down. Upshifting the chainring takes a longer throw and a little hold time to complete, but still a clean shift. Was concerned about the need to "trim" the FD, but that's easy too, and not needed often. In short, works great, better than expected.